In order to increase throughput for received signals in a Code Division Multiple Access (CDMA)-based packet transmission system, such as High Speed Packet Access (HSPA), an equalizer (EQ) has been proposed as an alternative to a widely-used existing rake (RAKE) receiver.
The EQ may increase throughput in comparison to the RAKE receiver, but has a problem in that its power consumption is high. Thus, the EQ is used along with the RAKE receiver, rather than instead of it. With regard to this, in order to minimize power consumption, the EQ performs only operations essential to demodulate a received signal; and the remaining operations are mainly performed by the RAKE receiver.
It is also possible to alternately operate the EQ and the RAKE receiver according to estimated signal-to-interference plus noise ratio (SINR) values. For example, The EQ may be operated in an area where an SINR has a higher value above a threshold, and the RAKE receiver may be operated in an area where an SINR has a lower value below the threshold. As the EQ is used in the higher SINR area, throughput for received signals may increase when compared to using the RAKE receiver.
However, when the RAKE receiver and EQ are alternately used according to SINR values, as mentioned above, it is impossible to always optimally operate the EQ and the RAKE receiver in a corresponding channel environment.
In a specific environment, either the RAKE receiver or the EQ is operated in order to prevent a ping-pong effect. The operation of the RAKE receiver or the EQ is determined based on whether or not a current SINR value falls within a range of SINR values, which is set for the operation of the RAKE receiver or the EQ.
However, when the current SINR value corresponds to a boundary value that is set to distinguish between the operations of the RAKE receiver and the EQ, there is no telling which of the RAKE receiver and the EQ may be operated. This may cause a problem in that, although the EQ can be more efficiently operated in a current channel environment, the RAKE receiver is actually operated. By reason of this, it is impossible to always optimally operate the RAKE receiver and the EQ in a corresponding channel environment.
In this way, many problems are involved in alternately operating a RAKE receiver and an EQ to minimize power consumption of the EQ. Therefore, there is a need for a signal reception method and apparatus that is robust to a change in channel environment and can minimize power consumption of an EQ.